def getAnswer(self):
n = 2
while True:
primes = [p for p in utility.getPrimes(pow(10, n))]
for p in primes:
if p < pow(10, n-1):
continue
for i in xrange(10):
if str(p).count('%d' % (i)) == 0:
continue
count = 0
for j in xrange(10):
if int(str(p)[0]) == i and j == 0:
continue
q = int(str(p).replace('%d' % (i), '%d' % (j)))
if p == q or utility.isPrime(q, primes):
count += 1
if count == 8:
return p
n += 1
def getAnswer(self): def isPermutations(p, q, r): p = str(p) q = str(q) r = str(r) for i in xrange(10): s = '%d' % i if p.count(s) != q.count(s) or q.count(s) != r.count(s): return False return True primes = utility.getPrimes(10000) for i in xrange(len(primes)): if primes[i] < 1000: continue for j in xrange(i + 1, len(primes)): p = primes[i] q = primes[j] r = q + q - p if r > 10000 or not utility.isPrime(r, primes): continue if not isPermutations(p, q, r): continue if p == 1487: continue return int(str(p) + str(q) + str(r)) return -1
def getAnswer(self): primeLimit = 10000 primes = utility.getPrimes(primeLimit) i = 0 n = 1 numPrime = 0 numTotal = 1 while True: i += 1 for j in xrange(4): n = n + 2 * i if n >= primeLimit * primeLimit: primeLimit *= 2 primes = utility.getPrimes(primeLimit) if utility.isPrime(n, primes): numPrime += 1 numTotal += 1 if numTotal > numPrime * 10: return i * 2 + 1
def f(limit): primes = utility.getPrimes(limit) length = 1 ret = 0 for i in xrange(len(primes)): for j in xrange(i + length, len(primes) - 1): s = sum(primes[i:j+1]) if s >= limit: break if s < limit and utility.isPrime(s, primes): length = len(primes[i:j+1]) ret = s return ret
from utility import isPrime, findPrime2
count = 0
for prime in findPrime2(1000000):
prime = str(prime)
for i in xrange(0, len(prime) - 1):
if not isPrime(int(prime[i+1:] + prime[:i+1])):
break
else:
count += 1
print count
def isPrime(n): return utility.isPrime(n, primes)
def isConcatenatedPrime(p, q, primes): return utility.isPrime(int(p + q), primes) and utility.isPrime(int(q + p), primes)